A system and method for transferring host data from a host server to a user device during a KVM session, using an HTML5 KVM/virtual media client running in a Web browser of a user device, is disclosed. The user device may run a Web browser that allows the user to select an image file which then appears as a new drive letter (e.g., a virtual drive) on the server system to be managed. The system and method bypass the inability of the read-only virtual drives to transfer files back to the HTML client of the user device by modifying the original files received from the user device, which are packaged and sent back to the user device via the persistent sandbox. In this manner, important log files and other data files generated from the host server may be received by the user device via a user-friendly Web browser.